Can you imagine waking up one morning to discover that all compasses are pointing south instead of north? The effect could cause geomagnetic health problems in up to 15% of the population of the planet.
It’s not as bizarre as it sounds. Earth’s magnetic field has flipped — though not overnight — many times throughout the planet’s history. Its dipole magnetic field, like that of a bar magnet, remains about the same intensity for thousands to millions of years, but for incompletely known reasons it occasionally weakens and, presumably over a few thousand years, reverses direction.
Now, a new study by a team of scientists from Italy, France, Columbia University and the University of California, Berkeley, demonstrates that the last magnetic reversal 786,000 years ago actually happened very quickly, in less than 100 years — roughly a human lifetime.
“It’s amazing how rapidly we see that reversal,” said UC Berkeley graduate student Courtney Sprain. “The paleomagnetic data are very well done. This is one of the best records we have so far of what happens during a reversal and how quickly these reversals can happen.”
How Humans Are Affected
Many animals can sense the Earth’s magnetic field, so why not people, asks Oleg Shumilov of the Institute of North Industrial Ecology Problems in Russia.
A 2006 review of research on cardiovascular health and disturbances in the geomagnetic field in the journal Surveys in Geophysics (DOI: 10.1007/s10712-006-9010-7) concluded that a link was possible between human health and geomagnetism and that the effects seemed to be more pronounced at high latitudes.
A 2006 Australian study, for example, also found a correlation between peaks in suicide numbers and geomagnetic activity (Bioelectromagnetics, vol. 27 p 155).
For the rest of the story: http://www.wakingtimes.com/2014/10/16/will-we-see-reversal-earths-magnetic-field/